This can be used as a "gee whiz" demonstration, or better as an
illustration of the basic idea of a strong oxidizer. If used for the
latter purpose, it should be presented as part of a discussion of oxidation and
reduction. The bottle label states that potassium chlorate is a strong oxidizer,
and this demonstration shows what that means.

Fill the test tube to a depth of about one inch with potassium chlorate.
Clamp the test tube in place at an approximately 45

°
angle. Set up the ringstand-clamp-test tube assembly behind a safety shield in
front of the class. Connect the burner so that the test tube can be heated
easily.

Light the burner and heat the test tube at the bottom until the solid melts
(mp is around 350

°
C). Stand behind the safety shield and carefully drop one gummi bear into the
test tube using tongs or forceps. A violent flame-shooting reaction ensues and
lasts for about one minute. You class will remember it for years!

DISCUSSION

The gummi bear is mostly sugar, which is easily oxidized by something like
molten potassium chlorate. Ideally, a balanced equation would show sucrose (C

12H22O11)
being converted to carbon dioxide and water while the KClO3
becomes KCl. The actual reaction does not seem to go to total completion since
there is usually a little gunky residue left behind.

HAZARDS

Molten KClO

3
can cause very severe burns. Think of your skin or the top of the lab
bench as another gummi bear. Exercise your best safety technique while
presenting this demonstration. It will set a good example for your class. There
is also a lot of smoke produced during the oxidation (steam and KCl?), so this
experiment should only be done in a room with good ventilation.